Joint Research Projects

1. Income and cost budgets for summer and winter crops in South Africa

   D van der Westhuizen
   The Bureau for Food and Agricultural Policy (BFAP)

   Background

   The Protein Research Foundation (PRF), Grain South Africa (GSA) and the Bureau for Food and Agricultural Policy (BFAP) currently have their individual cost of production programs which focusses on the key summer and winter crops produced in South Africa's key agro-ecological zones. Given the existing activities associated within the organisations and the extent of the coverage of South African agricultural production, it is envisaged that by collaboration and integration of existing activities by PRF, GSA and BFAP will add immense value to the individual organisations' annual output. The main objective is hence to consolidate the three programs, generate comprehensive crop income and cost budgets for the key summer and winter growing regions and lastly to generate sensitivity analysis for these crops based on the latest macroeconomic trends, BFAP Baseline underlying assumptions and international and domestic updates.

   In 2017, winter crop income and cost budgets were generated and submitted in April 2017. Thereafter, a number of stakeholder engagements occurred to refine methodology and output. A similar exercise was conducted for the summer crops and the BFAP team have met with the Soybean Work Group members to prepare the summer crops for the 2017/18 production season. In September, a first draft was circulated among the soybean workgroup and should be finalise by beginning October.

   Specific objectives

   Generate crop income- and cost budgets for key summer grains and oilseeds in selective regions in South Africa: Dryland: Mpumalanga / Eastern Highveld, Eastern Free State, Northern and Western Free State, North West and KwaZulu-Natal. Irrigation: Northern Cape, Brits, Limpopo and Bergville. Generate crop income and cost budgets for key winter grains and oilseeds in selective regions in South Africa:

   • Dryland:
     Eastern Free State, Southern Cape and Western Cape
   • Irrigation:
     Northern Cape, Brits, Limpopo and Bergville

   Generate sensitivity analysis for the above identified crops based on the latest market trends and projections.

2. Evaluation of PRF soybean elite lines under South African conditions

   Mr GP de Beer and Mr WF van Wyk
   Protein Research Foundation

   During the past season (2017/18), only two institutions participated in the soybean elite trials. They were EEAOC (Argentina) and EMBRAPA (Brazil).

   Forty-five (45) lines obtained from these two institutions were compared to five (5) South African cultivars at six (6) localities in South Africa. The six localities were representative of the most prominent soybean growing areas in the country.

   The plantings dates were as follows:

   • Potchefstroom (30 October 2017);
   • Bethlehem (1 November 2017);
   • Stoffberg (1 November 2017);
   • Ukulinga (10 November 2017);
   • Atlanta (22 November 2017) and
   • Pretoria (UP) (24 November 2017).

   The maturity groups (MG) of the 45 lines varied between MG 4,0 and MG 7,0. The five registered cultivars were MG 4,0; MG 4,2; MG 4,5; MG 6,0 and MG 7,2.

   Grain yields of more than 5,0 tonnes per hectare were achieved and only a few lines rendered higher yields than the registered cultivars. Six of the EEAOC lines and three of the EMBRAPA lines were selected for further tests at Sensako, aimed at possible registration as cultivars.

   Apart from the grain yield, valuable physiological characteristics such as flower colour, growth pattern (determined or indeterminate), leaf shape, toppling percentage, shattering percentage (seed attachment) and other were recorded. These characteristics are used in association with grain yield when selecting cultivars.

   This project has been terminated and will not be repeated in the forthcoming season. Positive results were achieves, such as five lines registered as cultivars, with another four lines being considered for registration. Additional lines are being tested by Sensako, aimed at submission for registration.

3. Management strategies for soilborne diseases of soybean in South Africa

   Dr YT Tewoldemedhin and Dr SC Lamprecht
   ARC – Research Institute for Plant Protection

   Seed treatment is a very important part of integrated management strategies against soilborne diseases of field crops. Surveys conducted in the major soybean production areas during 2010/11, 2011/12 and 2012/13 showed that many important soilborne pathogens are present in soybeans in South Africa. Many of these pathogens such as species within Fusarium, Pythium and Rhizoctonia affect seedling survival and establishment of soybean crops. In order to protect seedlings against these pathogens, glasshouse trials were conducted during 2014/15 and 2015/16 to evaluate fungicide seed treatments against damping-off and root rot caused by the most important soilborne pathogens. Three of the most effective treatments were selected for evaluation under field conditions. The current study therefore included the evaluation of the seed treatments Evergol (TR1), Celest XL+Apron XL (TR2), Maxim Quatro (TR3) and untreated seed (TR4) on three soybean cultivars viz DM 6.8i.RR, PAN 1454R and SSS 5052 in the cool (Bethlehem), moderate (Potchefstroom) and warm (Groblersdal) production areas. The field trials at Groblersdal and Potchefstroom were irrigated and the trial at Bethlehem was planted under dryland conditions. Soil was also collected from the trials to conduct similar tests under glasshouse conditions to evaluate the seed treatments on the three cultivars. The survival of seedlings at the three localities was recorded six weeks after planting. Seed treatment did not significantly affect survival of seedlings at each locality, however survival rates of seedlings from untreated seed at Bethlehem and Potchefstroom was lower than survival recorded for the other treatments. In non-pasteurised soil from Bethlehem and Potchefstroom under glasshouse conditions, all three treatments (TR1, TR2 and TR3) significantly improved survival of seedlings, but in Groblersdal soil there was no significant difference in survival of seedlings from untreated seed compared to seed treated with the different treatments. Although the survival of seedlings was highest six weeks after planting at Groblersdal, the grain yields were highest at Potchefstroom. It therefore appears that survival of seedlings is not always correlated with yield under field conditions and that other factors also affect yield. However, all three seed treatments increased grain yield at Bethlehem and Groblersdal and only TR1 increased yield with 2.1% at Potchefstroom. The increases in grain yield at Bethlehem were 15.3% (TR1), 13.9% (TR2) and 14.0% (TR3), and at Groblersdal yield increases were 22.2% (TR1), 11.6% (TR2) and 5.0% (TR3). Although these increases were not statistically significant, it is biologically significant and shows the huge impact that seed treatments can have on yield, but also that the same seed treatment can have a different effect at different localities. Treatment of seed with Evergol (TR1) significantly reduced growth of seedlings under glasshouse conditions, especially on seedlings younger than two weeks old and there were differences in the sensitivity of cultivars for growth reduction with PAN 1454R being more sensitive than the other two cultivars. However, despite the growth reduction in young seedlings, this seed treatment proved to be very effective in improving survival of seedlings and grain yield and also appears to be more effective for the control of Fusarium species that are pathogens of soybean seedlings than Celest XL + Apron XL (TR2). Soil pasteurisation and seed treatments TR1, TR2 and TR3 significantly reduced cotyledon and root rot severity for all three cultivars under glasshouse conditions. Treated seed plated to determine the effect of seed treatments on the incidence of seedborne fungi showed that, of the seven potential pathogens isolated from untreated seed, Colletorichum spp. could still be isolated from TR1 and TR2 treated seed and Fusarium equiseti and Diaporthe longicolla from TR2 treated seed. Surface disinfestation eliminated many of the seedborne fungi, however, Colletotrichum spp., F. equiseti, F. verticillioides and D. longicolla could still be isolated from surface disinfested seed. It is also important to note that fungi that were seedborne such as Colletotrichum spp., F. verticillioides and P. longicolla were often isolated at higher frequencies from seedlings planted in pasteurised compared to non-pasteurised soil which demonstrates the transmission of these pathogens from seed to seedlings. It is well-known that there is a complex of soilborne pathogens that affect soybean in field soil and that these complexes differ in different production areas and are affected by different soils and climatic conditions. From the results it is also clear that there were cultivar by seed treatment interactions for certain parameters indicating that certain treatments may be more beneficial to certain cultivars than others and certain seed treatments are better suited to certain production areas than others. The challenge was to identify a seed treatment that will benefit establishment and yield of most cultivars in most production areas under both dryland and irrigation systems. Although all three seed treatments improved grain yield of soybean under dryland (Bethlehem) and irrigation (Groblersdal) conditions, treatments TR1 and TR2 seemed to be more effective in increasing grain yield than TR3 and can contribute significantly to management of soilborne pathogens of soybean and therefore sustainable production of soybean in South Africa.

4. An evaluation of continuous cash crop production (including small grains, canola and other alternative broadleaf crops) under conservation agriculture principles on high potential soils of the Riversdale Flats

   JA Strauss
   Western Cape Department of Agriculture

   2017 was the 6th year of production on the new trial. Six cash crop systems are tested including shortened canola rotations and cover crops. Riversdale received very little summer rainfall which resulted in a very dry start to the 2017 production season. Only 35mm fell from January to the end of April. In 2017 a new weather station was installed at the research site which is managed by the Department of Agriculture. A total of 126mm rain was received from April to the end of September.

   Wheat production

   SST0127 was planted at Riversdale at 79kg/ha. A total of 53kg N/ha was applied to each plot (23kg N/ha at planting and 30kg N/ha topdressing). Wheat yields at Riversdale averaged 1 444kg/ha. This was 2 943kg/ha less than in 2016.

   Canola production

   Atomic TT was planted at Riversdale at 3.8kg/ha. A total of 25kg N/ha was applied to each plot. All the nitrogen was supplied at plant and no top dressings were made due to the climatic conditions. Canola yields at Riversdale averaged 1 211kg/ha. The oil content was just below 40% at all the plots.

   Barley production

   Agulhas was planted at Riversdale at 62kg/ha. Barley yields at Riversdale averaged 1 211kg/ha. This average yield was 2 933kg/ha less than in 2016. Yields varied between 765kg/ha and 1 431kg/ha.

   Lupin production

   Mandelup was available and was planted at Riversdale at 100kg/ha. No lupin plots were harvested due to poor germination and weed problems in the very low rainfall year.

   Cover crops

   Saia oats and a bitter lupin mix was planted at Riversdale at 29kg/ha and 100kg/ha, respectively. No other input cost was incurred during the season except the herbicide cost to kill the cover crop.

   Economics

   Although it proved to be a very poor production in 2017 year all systems tested show a positive gross margin above direct allocated production costs.

5. The influence of planting date and row width on recommended planting density and yield of soya beans in the north eastern Free State

   JP van Zyl
   Department of Agricultural Development, VKB

   Participating farmers and trail localities

   • Izak Dreyer (Vrede Ascent)
   • Jaco van Dyk (Vrede / Memel)
   • SW Graaff (Frankfort / Jim Fouché)
   • Jan Nell (trail was not planted due to unforeseen circumstances)

   Experimental site summary

   • Izak Dreyer
     • 2 x row widths: 0.38m and 0.76m
     • 1 x planting date: early
     • 4 x plant densities: 100 000, 200 000, 270 000, 400 000 plants/ha
     • 4x cultivars
       • SSS 4945 (NIG 4.5)
       • SSS 5449 (MG 5)
       • SSS 6560 (MG 6)
       • SSS 5202 (MG 5.2)
   • Jaco van Dyk
     • 1 x row widths: 0.76m
     • 1 x planting date: early
     • 4 x plant densities: 200 000, 300 000, 400 000, 500 000 plants/ha
     • 3 x cultivars
       • SSS 4945 (MG 4.5)
       • SSS 5449 (MG 5)
       • SSS 6560 (MG 6)
   • SW Graaff
     • 2 x row widths: 0.30m and 0.60in
     • 2 x planting date: early and late
     • 4 x plant densities: 200 000, 300 000, 400 000, 600 000 plant/ha
     • 4 x cultivars
       • SSS 4945 (MG 4.5)
       • SSS 5449 (MG 5)
       • SSS 6560 (MG 6)
       • SSS 5202 (MG 5.2)